Описание: Wind power is the conversion of wind energy by wind turbines into a useful form, such as electricity or mechanical energy. Large-scale wind farms are typically connected to the local power transmission network with small turbines used to provide electricity to isolated areas.

Introduction RelevanceIt is a very important issue, because everyday the world produces carbon dioxide that is released to the earths atmosphere and which will still be there in one hundred years time.

This increased content of Carbon Dioxide increases the warmth of our planet and is the main cause of the so called “Global Warming Effect”. One answer to global warming is to replace and retrofit current technologies with alternatives that have comparable or better performance, but do not emit carbon dioxide. We call this Alternate energy. According to experts oil and gas reserves will be exhausted in 40-50 years.By 2050, one-third of the world's energy will need to come from solar, wind, and other renewable resources. Climate change, population growth, and fossil fuel depletion mean that renewables will need to play a bigger role in the future.

Alternative energy refers to energy sources that have no undesired consequences. Renewable energy resources have lower carbon emissions, compared to conventional energy sources. The main aim of my work is study of various types ofenergy sources and identify their advantages and disadvantages .In my work I considered these types of renewable energy sources like wind power, hydropower, solar energy, biomass and nuclear.

Wind powerWind power is the conversion of wind energy by wind turbines into a useful form, such as electricity or mechanical energy. Large-scale wind farms are typically connected to the local power transmission network with small turbines used to provide electricity to isolated areas. Although wind produces only about 1.5% of worldwide electricity use, it is growing rapidly, having doubled in the three years between 2005 and 2008. In several countries it has achieved relatively high levels of penetration, accounting for approximately 19% of electricity production in Denmark, 11% in Spain and Portugal, and 7% in Germany and the Republic of Ireland in 2008. As of 2008, Europe leads the world in development of offshore wind power, due to strong wind resources and shallow water in the North Sea and the Baltic Sea. The technical potential of wind energy Russia is estimated more than 50 000 billion kWh / year. The economic potential is about 260 billion kWh / year, or about 30 percent of electricity production in Russia.

Wind energy zones in Russia are located on the coast and islands of the Arctic Ocean.The largest wind farm in Russia (5.1 MW) is located in the Kaliningrad region.

Advantages

Disadvantages

Clean Source

inconstancy

Renewable

Safety of People

Cost Effective

Expensive to Set Up

Rapid Growth and Huge Potential

Suitable to Certain Locations

Use of Modern Technology

Threat to Wildlife

HydropowerHydroelectricity is electricity generated by hydropower, i.e., the production of power through use of the gravitational force of falling or flowing water. It is the most widely used form of renewable energy. Once a hydroelectric complex is constructed, the project produces no direct waste. Small scale hydro or micro-hydro power has been an increasingly popular alternative energy source, especially in remote areas where other power sources are not viable. Small scale hydro power systems can be installed in small rivers or streams with little or no discernible environmental effect or disruption to fish migration. Most small scale hydro power systems make no use of a dam or major water diversion, but rather use water wheels to generate energy. Also, many hydropower projects are designed to serve specific industries. For 2006, hydropower production provides up to 88% renewable and 20% of all electricity in the world, hydropower installed capacity reaches 777 GW.

The absolute leader in the development of hydropower is Iceland. But her figure is highest in Norway, Canada and Sweden. In Paraguay, 100% of the energy produced is generated by hydropower plants.

The most active construction on the beginning of the 2000s leads China, for which hydropower is a major potential source of energy. In this country, posted the largest hydroelectric power station of the world "Three Gorges" on the Yangtze River.

Advantages

Disadvantages

Renewable

Methane emissions

Low cost of electricity

Ecosystem damage and loss of land

Reduced CO2 emissions

Siltation and flow shortage

Solar EnergySolar energy can be converted directly into heat and electricity.

The strength of the solar energy available at any point on the earth depends from the day of the year, the time of day, and the latitude of the collection point.

Solar energy is used for heating water for domestic use, space heating of buildings, drying agricultural products, and generating electrical energy.

One of the first examples of using solar energy was the used of a solar collector box to cook food during an expedition into Africa in the 1830's by British astronomer John Herschel. This is an economic solution as, by using the sun's heat for making our hot water, we cut down on the amount of fossil fuels needed to be burnt to supply electricity.

We are also able to harness radiant or solar light energy. Radiant energy is produced in the sun as a result of nuclear fusion reactions. This process is being used more and more as the technology is developed and becomes more economic. It is used widely in solar powered calculators and other such devices. Solar Thermal Electricity GenerationSolar thermal power plants use the sun's rays to heat a fluid, for the production of high pressure, high temperature steam. The steam, in turn, is converted into mechanical energy in a turbine. Currently there are three types of solar-thermal power systems in use or under development: the solar dish, solar power tower and parabolic trough. Solar photovoltaicsSome materials are sensitive to the sun's radiant or light energy and react in such a way that we can harness this "reaction" to produce electricity.

The sun's light energy can be converted directly into electricity in a single process using Photovoltaic cells, otherwise known as solar cells. A cell is a thin plate of light sensitive material of silicon

When the silicon is combined with one or more other materials, it exhibits unique electrical properties in the presence of sunlight. Electrons are excited by the light and move through the silicon. This is known as the photovoltaic effect and results in direct current electricity.

The Photovoltaic (PV) cell was discovered in the early 1950's by researchers examining the sensitivity of a silicon wafer to sunlight. By the late 1950s, PV's were used to power U.S. space satellites and this success generated commercial applications for PV technology. The simplest PV systems power small calculators and wrist watches used everyday, while more complicated systems provide electricity to pump water, power communications equipment, and even provide electricity to our homes.

Advantages

Disadvantages

No Pollution

Initial Cost

Renewable resources

Inefficiency

Low maintenance

Reliability

Easy Installation

Installation area

BiomassBiomass is a renewable energy because it contains the energy which comes from the sun. Biomass is basically an organic material made from plants and animals. Through the process of photosynthesis, chlorophyll present in plants absorbs the energy from the sun by converting the carbon-dioxide present in air and water from the ground in carbohydrates. The chemical energy that is present in plants is passed onto the animals and people that eat them.

So, when these plants and animals are burned they turn back into carbon dioxide and water and release the suns energy they contain. In this way, we can say that biomass is renewable source of energy because we can always produce more crops and plants and waste will always exist. As long as biomass is produced this source of renewable energy will last for ever. Examples of biomass include: plants, crops, trees and garbage.

Biomass in itself contains chemical energy. So, when you burn wood which is a biomass fuel, the chemical energy inside releases as heat. It can also be used to produce steam which can further be used to generate electricity. Using biomass for energy can cut back on waste and can also help in reducing the landfill.

So, crux of the point is biomass energy is renewable as the stored energy i.e. CO2 is release, recycled and reused. It is environment friendly as doesnt contribute to global warming and can be produced over and over again.

In 2002, the United States in the electricity was installed 9733 MW of generating capacity, biomass.

In 2003, 4% of the total US energy produced from biomass.

In 2004, around the world to produce electricity from biomass power plants with total capacity of 35,000 MW.

Currently, European countries are experimenting with growing energy forests for biomass production. On large plantations grown fast-growing trees: poplar, acacia, eucalyptus and others. Tested about 20 species of plants. Russia annually collects up to 300 million tons of dry organic waste equivalent of 250 million tons of agricultural production, 50 million tons in the form of household waste.

Advantages

Disadvantages

Widely Available

Expensive

Renewable resources

Requires Lot of Space

Carbon Neutral

Can Lead to Deforestation

Helps Reduce Waste

Not Totally Clean

Nuclear powerNuclear energy is another non-renewable source that has gained popularity in the last few years.Nuclear energy, as the term says, is released from the very nucleus of an atom. This happens as a result of its mass being converted to energy. Even though nuclear power is safer than burning electricity for fossil fuels, it is still a hazard to our health and the environment.

Nuclear power is produced through two different processes: Nuclear Fission and Nuclear Fusion.

Nuclear Fission

Nuclear fission is the process of releasing the atomic energy by splitting the nucleus thus creating two products of roughly half the mass of the original. A nuclear reactor splits the nuclei of uranium atoms, creating large amounts of energy. This process also creates radioactive waste and radiation, which can contaminate the environment. Nuclear fission is the physical process responsible for all types of power generation, including that used in both nuclear weapons and nuclear power plants.

Nuclear Fusion

Nuclear fusion is the energy source of the future. It is what provides the sun and the stars with the energy to shine continuously for billions of years. Nuclear fusion is when multiple atomic particles join together to create a larger atom. Fusion reactors join hydrogen atoms together to form helium atoms, neutrons and other forms of energy. This is the same type of nuclear energy used in hydrogen bombs. Fusion has been used here on earth to produce nuclear bombs, but has not yet been controlled so that we can obtain useful energy. Unlike nuclear fission, there is no limit on the amount of the fusion that can occur.

The Future of Nuclear Power

Nuclear energy is a powerful force. Attempts have been made to find other constructive ways of harnessing it. Nuclear power is an important source ofenergyin many countries. 442 nuclear reactors are now operating worldwide with a total capacity of 300,000 MW. Two and a half times this number will be added by 2030 and four times as many by 2050, says the International Atomic Energy Agency, the bastion of the global nuclear community.

Higher oil and gas prices make alternatives such as nuclear power more attractive and are expected to lead to growth in nuclear generating capacity worldwide. Improvements in reactor design enhance safety, increase efficiency, and reduce costs, making nuclear generation an economically attractive source of energy. Many countries, including the UK, have recently affirmed their intention to continue their use of nuclear energy for electricity generation, and although this decision has been condemned by anti-nuclear pressure groups, all the indications are that nuclear power will continue to be an important source of energy for us for a long time to come.

Environmental concerns about the disposal of spent nuclear fuel persist, and countries are addressing those concerns in different ways. The US is developing a disposal facility on government property, but this solution is itself controversial.

Advantages

Disadvantages

Low Pollution

Environmental Impact

Low Operating Costs

Radioactive Waste Disposal

Reliability

Nuclear Accidents

More Proficient Than Fossil Fuels

High Cost

The Advantages and Disadvantages of Renewable Energy

The Advantages of Renewable Energy

One major advantage with the use of renewable energy is that as it is renewable.

Renewable energy facilities generally require less maintenance than traditional generators. Their fuel being derived from natural and available resources reduces the costs of operation.

Even more importantly, renewable energy produces little or no waste products such as carbon dioxide or other chemical pollutants, so has minimal impact on the environment.

Renewable energy projects can also bring economic benefits to many regional areas, as most projects are located away from large urban centres and suburbs of the capital cities. These economic benefits may be from the increased use of local services as well as tourism.

The Disadvantages of Renewable Energy

One disadvantage with renewable energy is that it is difficult to generate the quantities of electricity that are as large as those produced by traditional fossil fuel generators. This may mean that we need to reduce the amount of energy we use or simply build more energy facilities. It also indicates that the best solution to our energy problems may be to have a balance of many different power sources.

Another disadvantage of renewable energy sources is the reliability of supply. For example:renewable energy often relies on the weather. Hydro generators need rain to fill dams to supply flowing water. Wind turbines need wind to turn the blades, and solar collectors need clear skies and sunshine.

The current cost of the technology of renewable energy much larger than cost of traditional systems

ConclusionThe aim of my work was to review the various types of alternative energy sources such as solar, wind energy, biomass energy, nuclear power and hydropower.Each source has its own advantages and disadvantages.Source selection depends on many factors such as climate, location, number of sunny days and rain and mineral reserves.I can conclude that despite the disadvantages of renewable energy have a large number of advantages: renewable,no pollution and environmental.Reserves of traditional energy resources are depleted every year. The need to fight for a better environment, new opportunities to improve the quality of life, participation in international development of advanced technologies, the desire to improve the energy efficiency of economic development, the logic of international cooperation - these and other considerations contributed to the intensification of national efforts to create more green energy, move to a low carbon economy.Therefore I think the competent and rational use of renewable energy sources efficiently and economically justifiedUse of renewable energy sources will help us to save much more money and also help the environment.